First please excuse me if my english is too bad but I'm french.
I've a question.
for example you have

and the flop :

.
ther you are on a flush draw. so 1/3 to win.
I've heard that if you pay 1/3 that you can win, it's not a bad call.
But Don't you thnk that you should take care of the blinds value and How much bets you have ?